Controlling plant height of perennial ornamentals in the nursery

摘要

For many perennial ornamental plants grown in container nurseries, effective height suppression is often difficult. Previous research has shown that combinations of plant growth regulators (PGR) may reduce height growth in some perennial species. The purpose of these trials is to further test different species. All plants were in one gallon, black plastic containers, and field grown. Standard nursery irrigation and fertilization practices were maintained throughout the trial. Test plants were arranged in a completely randomized block design with four replications per treatment. A handheld pressurized sprayer was used for chemical application of foliar sprays at a rate of 2 quarts per 100 sq ft. The treatment date was July 1, 1999. Three weeks after treatment (WAT), the paclobutrazol application resulted in significant height reduction in Artemisia and Gaura. At 5 WAT, Artemisia and Hemerocallis showed growth reduction, with the paclobutrazol application. The Gaura trial was concluded 3 WAT sinceall plants were in full bloom. The Artemisia and Hemerocallis plants treated with paclobutrazol also had delayed flowering compared to all other treatments.